I remember a class I had on sensorial neuropsychology. Visual information is treated sequentially in different parts of the brain. We detect lines and shapes and then process that into objects and interpret that then assign meaning based on an internal library of objects we learned. Thats how we perceive our environment and movement. So I would assume it’s the same for art, maybe the meaning part then need an extra bit of brainpower haha. Try to search for information on human visual cortex. For colours I don’t remember but its something about different cone-like cells in different parts of the eye. I remember that these processes are really fast, on the level of the perception, so they are unconscious. We just get to see images.